Holman was the author of poetry, short fiction, essays, and plays, and a civil rights leader. He is best known for his play The Baptizin' (1971), his poem "Mr. Z," and a nonfiction overview of the civil rights movement in the US from 1965 to 1975. His work is also included in the anthology Anger, and Beyond: The Negro Writer in the United States (1964).

In 1962, Holman moved to DC to work at the United States Civil Rights Commission, becoming its Deputy Director in 1966. From 1971 to 1988, he served as Director of the National Urban Coalition, an organization formed after the riots of 1967, where he advocated for programs in housing, education, employment and economic development. Holman was known for his ability to work behind-the-scenes, and to create alliances between African Americans and Jews and Latinos. He lived in DC until his death at age 69. He is buried in Rock Creek Cemetery.